Noyes Education Campus, a kindergarten through 8th grade school in Washington, D.C., is seen in February 2011. / Jack Gruber, USA TODAY

by Greg Toppo, USA TODAY

by Greg Toppo, USA TODAY

A new documentary raises questions about whether Washington, D.C., school officials downplayed allegations that educators were cheating to improve students' scores on high-stakes skills tests - even after a principal came forward with her own eyewitness account.

Washington's Noyes Education Campus was the subject of a 2011 investigative series by USA TODAY, which first reported on unusually high numbers of wrong-to-right pencil erasures on standardized test papers going back to 2008.

Administered citywide each spring, the math and reading exams gained new prominence in 2007, after then-chancellor Michelle Rhee began tying student scores to principals' and teachers' employment.

The PBS Frontline documentary "The Education of Michelle Rhee," airing Tuesday, offers the first testimony from Adell Cothorne, who in the 2010-11 school year was principal at Noyes. Cothorne tells the filmmakers that she alerted officials on Nov. 3, 2010, to an afterschool incident in which she stumbled upon three staffers sitting in an office with students' completed practice test booklets and pencils.

"I noticed that the erasers were down and the pencil points were up," Cothorne said Monday in an interview. "That really stuck out in my mind."

She immediately reported the incident, but was never contacted by administrators. "I kind of trusted that somebody would follow through on it and it didn't really happen that way," Cothorne said.

Cothorne filed a federal complaint against the district in 2011, alleging that cheating essentially defrauded the U.S. government, since Washington receives millions in federal funds annually for education. That triggered an investigation by the U.S. Department of Education, which said on Monday that cheating was limited to just one school, which it didn't specify. The department said it couldn't substantiate any false claims and the U.S. Department of Justice declined to intervene.

In the complaint, newly unsealed, Cothorne alleges that shortly after she stumbled upon the staffers erasing test papers, former Noyes principal Wayne Ryan called her to his office and told her, "I heard that you don't respect the legacy that has been built at Noyes." She said Ryan told her, "You're not saying anything" about erasures.

Ryan couldn't be reached immediately for comment.

Cothorne requested extra security for the high-stakes tests the following spring and students scores dropped about 25 percentage points.

In a statement, D.C. Public Schools spokeswoman Melissa Salmanowitz said every report of testing impropriety "is taken very seriously." She noted that Cothorne was interviewed by a private firm as part of a separate investigation of the 2010-11 tests "and there is no mention of this incident in the interview report."

After USA TODAY wrote about Noyes in March 2011, the city's inspector general launched what would become a 17-month investigation that included interviews with Cothorne's entire staff, but not her. "I just figured they didn't want to hear what I had to say," she said. That report focused solely on Noyes and found no reason for a wider probe of Washington schools.

The Frontline documentary includes comments from a USA TODAY reporter who worked on the 2011 investigative series.